Roll changers

ABSTRACT

An automatic work roll changer for a continuous rolling mill in which stools are located on the operator side so that they can be positioned between the operator side work roll chocks and the drive work roll chocks as the work rolls are changed.

United States Patent [191 Eibe et a1. 1

1 Feb. 11, 1975 ROLL CHANGERS [75] Inventors: Werner W. Eibe; AndrewAndrascik, both of Pittsburgh, Pa.

[73] Assignee: Blow-Knox Foundry & Mill Machinery, Inc., Pittsburgh, Pa.

[22] Filed: Dec. 4, 1973 [21] Appl. No; 421,584

[52] U.S. Cl. 72/238, 72/239 [51] Int. Cl B2lb 31/08 [58] Field ofSearch 72/238, 239

[56] References Cited UNITED STATES PATENTS 3,436,945 4/1969 Karnkowski72/239 3,443,410 5/1969 Beck 72/239 3,540,253 11/1970 Kollek et a1.72/239 3,552,171 1/1971 Shumakel' 72/239 3,611,779 10/1971 Simmonds72/239 3,699,796 10/1972 Eibe 72/239 3,747,387 7/1973 Shumaker 72/2393,754,426 8/1973 Adair 72/238 Primary ExaminerMilton S. Mehr Attorney,Agent. or Firm-Smith, Harding, Earley & Follmer [57] ABSTRACT Anautomatic work roll changer for a continuous rolling mill in whichstools are located on the operator side so that they can be positionedbetween the operator side work roll chocks and the drive work rollchocks as the work rolls are changed.

17 Claims, 8 Drawing Figures PATENTEI] FEB] 1 i975 SHEEI 2 BF. 6

ROLL CHANGERS BACKGROUND OF THE INVENTION This invention relatesgenerally to roll changers and particularly to apparatus forautomatically changing the work rolls of a continuous rolling mill.

The problem of changing the work rolls of a rolling mill has become amanner of increasing importance in the efficient operation of modernrolling mills. With modern high speed rolling mills it is frequenlynecessary to change work rolls several times each shift because of thechanging nature of the orders available, because of steel analysis, orfor any of a variety of reasons recognized in the trade. In the past,rolls were changed by overhead cranes using counterweighted yokes orcradles for individually handling a roll into and out of the rollingmill housing. Such methods were excessively wasteful of time andmanpower. More recently, automatic work roll changers have been providedsuch as, for example, the roll changers shown in US. Pat. Nos. 3,698,226and 3,699,796. However, such work roll changers cannot be used withcontinuous rolling mills since such mills always have some strip in themill and it is necessary to move the work rolls and work roll chocksacross the strip into and out of the mill without interferring with thestrip.

Another problem in work roll changers is that the the location of a rollchanging car on the floor of the mill in a roll changing positionadjacent the mill makes this entire area inaccessible to workmen.

SUMMARY OF THE INVENTION The present invention provides a roll changerdesign particularly adapted for the rapid automatic work roll changingof a continuous rolling mill. The roll changer in accordance with theinvention has provision for supporting the work roll chocks and the workrolls supported thereby in a separated condition as it moves across thestrip in the mill to avoid interference therewith and means forinserting stools between the operator side work roll chocks and betweenthe drive work roll chock to maintain this separated condition as thework rolls are moved out of the mill for transfer to a roll changing caroutside of the mill.

Briefly stated, the design in accordance with the invention comprises arolling mill having upper and lower work rolls defining a passline forthe strip to be rolled therebetween, an operator side mill housingdefining a window, upper and lower work roll chocks for rotatablysupporting the upper and lower work rolls and adapted to be removablymounted in said operator side housing, a mill housing on the drive sideof the mill defining a window, an upper and lower work roll chock forrotatably supporting the upper and lower work rolls on the drive side ofthe mill and adapted to be removably mounted in said drive side housingwindow, means for supporting said work roll chock and said work rollssupported thereby in a separated condition during movement thereofinside of the mill housing, and means for supporting said work rollchocks and the work roll supported thereby in separated condition duringmovement outside of the mill housing, said lastnamed means comprisingfirst stool means positioned within said operator side housing andadapted to be positioned between said operator side work roll chocks andsecond stool means positioned within said operator side housing andadapted to be positioned between said drive side work roll chocks.

In order to provide access to the mill during rolling in the rollchanging area adjacent thereto, there is provided a roll changing carwhich is maintained under the floor of the mill during rolling and whichincludes floo'r plates providing the floor area. The roll changing carcan be opened up to a'roll changing position with the floor platesforming the rails on which the work rolls are supported outside the millduring the changing operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary elevationalview of the operator side housing of a rolling mill provided with theroll changer changing apparatus in accordance with the invention;

FIG. 2 is a vertical section of the work roll region of the rolling millshown in FIG. 1;

FIG. 3 is a sectional view taken generally on line 33 of FIG. 2;

FIG. 4 is a sectional view taken generally on line 44 of FIG. 2;

FIG. 5 is a plan view of the roll changing area;

FIG. 6 is a vertical section of the roller changing area;

FIG. 7 is a section taken generally on line 7-7 of FIG. 5;

FIG. 8 is a sectional view taken generally on line 88 of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1,there is shown a mill housing 10 which is located on the operator sideof the mill. Housing 10 provides a window 12 adapted to contain an upperwork roll chock 14 and a lower work roll chock 16 which conventionallysupport an upper work roll 18 and a lower work roll 20, respectively,which define a pass line 21. Window 12 is also adapted to contain anupper back-up roll chock 22 and a lower back-up roll chock 24 whichconventionally support an upper backup roll 26 and a lower back-up roll28, respectively. As is conventional in the art, there is provided ascrewdown means 27 at the upper endof the mill engaging the upperback-up roll chock 22 and a hydraulic force applicator 29 at the lowerend of the mill engaging the lower back-up roll chock 24.

At the drive side of the mill there is provided a mill housing 10 whichis similar to the housing 10. As is shown in FIG. 4, housing 10'provides a window 12 adapted to contain an upper work roll chock 14' anda lower work roll chock 16 which conventionally supports the upper workroll 18 and the lower work roll 20, respectively. Window 12 alsocontains upper and lower back-up roll chocks (not shown) as isconventional in the art.

A pair of spaced apart upper inside rails 30 are positioned withinwindows 12 and 12 to extend from the drive side housing 10' to theoperator side housing 10. Upper rails 30 are supported on a pair ofhydraulic cylinder means 32 positioned in each of the housing 10 and 10,the rails 30 being supported on the upper end of the actuator rod ofsuch cylinder means as is best shown in FIG. 2. The upper work rollchocks l4 and 14' are supported on the upper rails 30 by means of wheelmeans 34, 34 carried on outwardly extending arms 36, 36' of the workroll chocks 14 and 14' extend- 3 ing arms 36, 36' of the work rollchocks 14 and 14' respectively.

The hydraulic cylinder means 32 serve to raise and lower the upper rails30, and in turn the upper work roll chocks supported thereon, the raisedposition of the rails 30 being shown in the left side of FIG. 2 (theroll changing position) and the lower position of the rails 30 beingshown in the right side of FIG. 2 (the normal rolling position). Thehydraulic cylinder means 32 also serve as a crown out force applicatormeans for the upper work roll.

A pair of spaced apart lower inside rails 40 are positioned within thewindows 12 and 12' to extend from the drive side housing to operatorside housing 10. Lower rails 40 are mounted, by means of bolts, on thehousing means 10 and 10 directly below wheel means 42, 42' mounted onthe lower work roll chocks l6 and 16'. A pair of hydraulic cylindermeans 44 mounted in each of the housing members 10 and 10' are raised toengage outwardly extending ears 46 on the lower chocks l6 and 16' toraise and lower the chocks between the lower position shown on the leftside of FIG. 2 and the upper position shown on the right side of FIG. 2.At the left side of this figure the wheel means 42 rest on the lowerrails 40 whereas at the right side the wheel means 42 are spaced abovethe rails 40 during the rolling of the mill. The cylinder means 44 alsoserves as the crown-out cylinders for the lower work rolls 20, suchcylinder means applying a force to the work rolls to reduce the crownthereof.

By means of the above-described construction, the inside rails 30 and 40in cooperation with the wheel means associated with the work roll chocksserve to support the upper and lower work rolls 18 and for movement intoand out of the mill in the region between the mill housings 10 and 10.Moreover, such arrangement provides that the work roll chocks aremaintained in a separated condition whereby the chocks 14' and 16 at thedrive side of the mill can be moved passed the strip extending along thepass line 21 which would be the case in a continuous rolling mill.

In accordance with the invention, novel means are provided frommaintaining the work rolls in this separated condition when they areoutside of the mill to permit an automatic work roll change. To thisend, there are provided an operator side stool means 50 comprising apair of stools 52 interconnected by a rod 54, each stool having a cutout56 formed therein to fit around a pair of stool supporting rails 58mounted by bolts 55 on an insert 11 in housing 10. Rails 58 are locatedwithin the window 12 at a location between the work roll chocks l4 and16.

There is also provided a drive side stool means 60 essentially the sameas operator side stool means 50 and comprising a pair of stools 62interconnected by a rod 64, each stool 62 having a cutout portion 66formed therein so as to fit around the rails 58.

Operator side work roll chocks 14 and 16 are provided with opposedcavities 70 and 72, respectively adapted to receive operator side stools52. The stools 52 would be contained within the cavities 70 and 72during a rolling operation. As shown in FIG. 4, in the roll changingcondition of the work roll chocks l4 and 16, the vertically extendingouter walls 74 and 76 of cavities 70 and 72 serve to limit the movementof the stools 52 relative to the chocks l4 and 16 in the directiontoward the ouside of the mill.

Chocks 14 and 16 are provided with opposed cavities 80 and 82respectively, which join with cavities and 72 respectively and extendtherefrom in the direction toward the inside of the mill. Cavities and82 are constructed to permit relative movement between chocks 14 and 16and the stools 52 between the solid line position and the dashed lineposition shown in FIG. 4. Cavities 80 and 82 are provided withvertically extending walls 84 and 86, respectively, which serve to limitsuch relative movement at the dashed line position. Each cavity 82 isprovided with an inclined bottom wall which contacts a similar inclinedbottom wall on each stool 52 during the relative movement.

A spring biased latch means 57 is mounted on each rail 58 and isarranged to engage a latch cavity in each stool 52 for holding the sameon the rail 58 at the solid line position shown in FIG. 4. The rails 58are provided with an inclined top surface portion 61 which cooperateswith a similar poriton of the cutout 56 to limit the movement of thestools 52 along the rails 58 in the direction toward the inside of themill at the solid line position shown in FIG. 4.

The operator side work roll chocks l4 and 16 are also provided withopposed cavities and 92 respectively, adapted to receive the drive sidestools 62, such stools being adapted to be contained within the cavities90 and 92 during a rolling operation. As shown in FIG. 4, in the rollchanging position of the work roll chocks l4 and 16, verticallyextending walls 94 and 96 of cavities 90 and 92 respectively serve tolimit movement of the stools 62 relative to chocks 14 and 16 in thedirection toward the outside of the mill. Cavities 90 and 92 are open inthe side facing the inside of the mill.

Spring biased latch means 59 are mounted on each of the rails 58 andarranged to engage an associated latch cavity in each stool 62 forholding the same on an associated rail 58 at the solid position shown inFIG. 4. Each of the rails 58 is also provided with an inclined topsurface portion 63 above the latch means 59 which cooperates with anassociated cutout 66 of an associated stool 62 to limit the relativemovement of the stool 62 on the rail 58 at the solid line position shownin FIG. 4.

The drive side work roll chocks I4 and 16 are provided with a pair ofopposed cavities 100 and 102, respectively, which are aligned withcavities 90 and 92 and are open on the side facing those cavities, i.e.,the inside of the mill. Cavities 100 and 102 have vertical walls 104 and106 respectively which are adapted to engage a vertical wall of thestools 62 and an inclined bottom wall 103 adapted to contact an inclinedbottom wall 65 of each stool 62. By this arrangement as the drive sidework roll chocks 14' and 16' are moved toward the outside of the mill(to the left as viewed in FIG. 4), each stool 62 is moved into thecavities 100 and 102 to come to rest at the position indicated by thedashed line showing of stool 62 in FIG. 4. The manner in which this isaccomplished and the purpose thereof during a work roll changingoperation will appear hereafter.

Work roll changing means is provided for pulling the separated workrolls from an opened mill and for pushing a new set of work rolls backinto the mill. Such means is best illustrated in FIG. 5 to 8 andcomprises a long stroke roll changing cylinder means 110 supported onthe underside of a movable floor plate structure 112, the floor line ofthe mill being indicated at 113 in FIG. 6. Connected to the extended endof the actuator rod 114 of cylinder means 110 is a hook means 116provided with a plurality of rollers 118 arranged to ride inhorizontally extending channel tracks 120 beneath the floor 112. At theend of the hook means 116 there is provided a hook 117 adapted to engagea cooperating hook portion 122 formed in the lower work roll chock 16.The rollers 118 closest to the mill are adapted to ride in a downwardlyextending pair of channel tracks 124 so as to guide the hook means 116as it moves between the raised solid line position and the dashed lowerposition shown at the left end in FIG. 6. In its upper position, thehook means 116 is engagable with the work roll chocks so as to cause themovement thereof into or out of the mill. In its lower position, hookmeans are located below the floor line 113. The floor 112 is providedwith a slot 115 adapted to permit the hook means 116 to movetherethrough as it is moved between the upper and lower positionsthereof.

Located between the floor 112 and the mill is roll transfer bed 130adapted to support a side shift car 132. Bed 130 is constructed of aplurality of beam members connected together and supported below thefloor line 114 on the foundation. The side shift car 132 is movable backand forth in the direction of strip movement through the mill on aplurality of rails 134 on the bed 130, the shift car 132 having wheels136 arranged to ride on rails 134 as best shown in FIG. 6. The back andforth shifting movement of the car 132 is caused by a hydraulic cylindermeans 138 which has its actuator arm connected to the side shift car 132at the connection 139.

The side shift car 132 also comprises means for providing the floor areain the region adjacent the mill, such means comprising five floor plates'140, 142, 144, I46 and 148. As shown in FIG. 8, floor plates 140, 142,I46 and 148 are pivotally mounted for movement on pivot bars 150, 152,156 and 158, respectively, for movement between an upright solid lineposition and a horizontally extending dashed line position. In the solidline position, the floor plates 140, 142, 146 and 148 are adapted toserve as rails for supporting the movement of the work rolls into andcout of the mill, wherefore the upper ends thereof are adapted to bealigned with the rails 140 inside the mill. The rail portions of floorplates 140, 14,2, 146 and 148 are provided with wheel stops 240, 242,246 and 248, respectively, best shown in FIG. 5. In the horizontalposition, the floor plates 140, 142, 146 and 148 serve to provide thefloor portion in the region adjacent the mill as is best illustrated inFIG. 5. Since the floor area is now clear of any roll changing car theoperators of the mill can move around in this area during the rollingoperation and at other times.

The pivotal mounting for each of the floor plates 140, I42, 146 and 148is similar. Floor plate 140 is mounted at its underside on a pluralityof vertically extending plates secured to and spaced along horizontallyextending pivot bar 150. Floor plate 142 is mounted at its underside ona plurality of vertical plates 162 secured to and spaced along pivot bar152. Floor plate 146 is mounted at its underside on a plurality ofvertical plates 166 secured to and spaced along pivot bar 156. Floorplate 148 is mounted at its underside on a plurality of vertical plates168 secured to and spaced along pivot bar 158. One of the plates 160 isinterconnected with an associated plate 162 by a link 161. Also one ofthe plates 166 is innerconnected with a generally aligned plate 168 by alink 167.

Means are provided for actuating the pivoted floor plates between theupright and horizontal positions thereof. Such means comprises ahydraulic cylinder means 170 pivoted on the side care at pivot 172 atone end and having its actuator rod 174 pivotally connected to one ofthe plates 160. By this arrangement, cylinder means 170 is operable toactuate the floor plates 140 and 142 between the upright and horizontalposition thereof shown in FIG. 8. Thus, when the actuator rod 174 isextended as is shown in solid lines in FIG. 8, the floor plates 140 and142 will be in the upright position thereof. When cylinder means 170 isactuated to retract the actuator rod 174, the floor plates 140 and 142will be moved to the dashed line horizontal position thereof definingthe floor. It will be apparent that the link 161 maintains a conjointmovement of the floor plates 140 and 142. Floor plates 146 and 148 aresimilarly aactuated betweentheir upright and horizontal positions bymeans of a hydraulic cylinder means 176 pivoted at one end on the shiftcar 132 at pivot 172 and having its actuator rod 178 connected to one ofthe plates 168. The conjoint movement between the floor plates 146 and148 is achieved by means of the link 167.

Side car 132 comprises two pairs of spaced apart track channels 180 and181 which are adapted to be aligned with the track channels by the sideshifting movement of the car. The track channels 180 and 181 alsoconform to track channels 120 and thus provide a track guide means forthe rollers 118 of the hook means 116 as it moves toward or away fromthe mill. As is shown in FIG. 8, the trace channels 180 are centeredwith respect to the upper rail forming ends of the floor plates and 142in their upright position while the track channels 181 are centered withrespect to the upper rail forming ends of the floor plates 146 and 148.

The track channels 180 are supported on a plurality of verticallyextending supports 182, 184 and 186 spaced along the tracks. Supports184 also serve to support the non-pivoting floor plate 144. The floorplate 144 is provided with a plurality of slots 143 adapted to permitthe movement therethrough of the vertical plates 162 and slots to permitthe movement therethrough of vertical plates 166 as the floor platesmove between the upright and horizontal positions thereof.

Located adjacent the side of floor plate 140 is a pivotally supportedfloor plate 190 which has located adjacent thereto a fixed floor plate192. Located adjacent the side of floor plate 148 is a fixed floor plate194.

Located between the floor plates 140 and 142 and the mill are a pair ofwalkway doors 140' and 142. The walkway doors 140 and 142 areconstructed and arranged in essentially the same manner as the floorplates 140 and 142 wherefore corresponding parts have been given likereference numerals with primes added. Thus, the walkway doors 140' and142' are actuated between a horizontal position providing a floor areaas shown in FIG. 5 and an upright position providing verticallyextending rails in continuation of the rails defined by plates 140 and142 as shown in FIG. 6. This movement is achieved by a hydrauliccylinder means which is connected to vertical plates mounted on a pivotmeans and secured to the underside of the plates 140' and 142'. Thecylinder means170' is supported on a stationary framework 132. There areprovided interconnecting links 161 and track channels 180 which arealigned with the channels 180 as is best shown in FIG. 6. The channels180' provide a guide means for the rollers 118 of the hook means 116.Since the walkway doors 140' and 142' are supported on a framework 132'which is fixedly supported on the bed 130, these doors are not actuatedthrough a side shifting movement along with the doors 140 and 142mounted on the side shift car 132.

The operation of the roll changer in accordance with the invention inautomatically changing a worn set of work rolls and replacing them witha new set of work rolls will now be described. In describing thisprocedure let it be assumed that the roll changing apparatus is in theposition illustrated in FIG. with the floor plates 140, 142, 146 and 148in their horizontal position and the hook means 116 is positioned belowthe floor line as is indicated by the dashed line showing of FIG. 6. Thefirst step is to actuate the cylinder means 176 to extend its actuatorrod 178 to move the floor plates 146 and 148 from the horizontalposition to the upright position as is illustrated in FIG. 8. The newrolls are then placed on the rails 146 and 148 as shown in dashed linesin FIG. 8 by suitable means known in the art. The work rollswill bepositioned one above the other in a separated condition which ismaintained by a set of stool means 50 and 60. Thus, the stool means 50are positioned between the work roll chocks l4 and 16 and the stoolmeans 60 are positioned between the work roll chocks 14 and 16. Thegeneral location of the stool means 50 and 60 is illustrated by thedashed line showings of the stool members 52 and 62 in FIG. 4 which arelocated respectively in the cavities 80 and 82 of chocks 14 and 16 andin the cavities 100 and 102 in the drive side work roll chocks 14' and16.

The next few steps involve getting as many parts as possible preparedbefore the mill is stopped. This involves opening the other set of railsprovided by the floor plates 140 and 142 by actuating hydraulic cylindermeans 170 to extend its actuator rod 174 to place plates 140 and 142 inthe position shown in FIG. 8. Also, the cylinder means 170' is actuatedto place the floor plates 140 and 142' in the upright position alignedwith the floor plates 140 and 142. Also, long stroke cylinder means 110is actuated to extend its actuator rod 114 toward the mill to positionthe hook means 116 immediately adjacent the mill. During this movementthe hook means 116 is first moved from the dotted line position to thesolid line position shown at the left end in FIG. 6 and then is furtheradvanced to the dashed line position shown adjacent the mill. Duringthis movement the rollers 118 move through channel portions 120, 180 and180' in that order.

The next step is to stop the rolling operation of the mill and to thenopen the mill, i.e., move the backup rolls and the work roll chocks fromthe rolling position to the separated position shown in the left side ofFIG. 2. This is achieved by the actuation of the hydraulic cylindermeans shown in FIGS. 1 and 2 and is conventional. FIG. 4 alsoillustrates the condition of the work rolls and work roll chocks andother parts at this stage in the work roll changing operation. The stepinvolves raising the upper backup roll chocks 22 by hydraulic cylindermeans 23, raising the upper work roll chocks by hydraulic cylinder means32 acting through upper rails 30, and lowering the lower work rollchocks onto rails 40 by retracting hydraulic cylinder means 44.

It will be noted that the work rolls 18 and 20 and the work roll chockssupporting the same are spaced above and below the pass line 21 of themill whereat the strip is located in the case of a continuous rollingmill. Also the wheels 42 on the lower work roll chocks are supported onthe lower rails 40 and the wheels 34 on the upper work roll chocks aresupported on the upper rails 30.

The chock clamps on the side are now opened as is conventional in theart.

The hook means 116 is then engaged in the hook member 122 on the lowerwork roll chock 16 and the long stroke cylinder is actuated to retractthe rolls to the position shown in FIG. 6. At this point the wheels 42on the lower work roll chock 16 come into contact with stops 240 and 242on the rails and 142. The movement of the rolls is arrested when thewheels 42 come into contact with the stops. About two inches prior tothis position, the track supporting rollers 118 drop downwardly into theinclined tracks 124 to release their engagement with the hook member122. The hook means 116 then returns to the lower position shown indashed lines-in FIG. 6. During this retracting movement the rollers 118move in order through track channels and 180 and 120. The worn workrolls which have been pulled from the mill now rest on the upper railportion of plates 140 and 142 with the wheels 42 of the lower work rollchocks being supported at the upper ends of these floor plates 140 and142 and against stops 240 and 242.

Cylinder means 138 is then actuated to extend its actuator rod and causea side shifting movement of the side shift car 132. This places thefloor plates 146 and 148 at the position where the floor plates 140 and142 were and places the new work rolls in line with the mill. This alsoplaces the hook means 116 in engagement with the hook portion 122 of thework roll chocks for the new work rolls.

It is noted that the floor plate 140 is provided with two curved ribs340 which are arranged to come in contact with the edge of the floorplate during the last portion of the side shifting movement of the sideshift car 132 to cause the floor plate 190 to pivot upwardly. Thismovement serves to lift the floor plate 190 out of the way to avoidobstruction with the side shifting car 132 during the side shiftmovement.

The long stroke cylinder 110 is then actuated to extend its actuator rod114 to thereby push the new work rolls into theopen mill. During thismovement the rollers 118 pass through track channels 120, 181 (whichhave now been moved to the position formally occupied by track channels180) and track channels 180'.

The mill is now closed in accordance with conventional procedures by theactuation of the cylinder means in the mill and the hook means iswithdrawn to the dashed line showing at the left end of FIG. 6. The wornwork rolls are then removed for repair, the side shift car 132 isreturned to the left position shown in FIG. 8 and the floor plates 140,142, 146 and 148 are returned to the horizontal position providing aflat floor. Hinged floor portion 190 is then also returned to thehorizontal position shown in FIGS. 5 and 8.

It will be evident that in the above description as the work roll chocksare moved out of the mill (to the left as viewed in FIG. 4), the chocksare initially carried by the rails 30 and 40 in the mill. As theoperator side work roll chocks l4 and 16 move to the left from theposition shown in FIG. 4 they will initially pick up, in the cavities 80and 82, the operator side stool members -52 which will be located inessentially the dashed line position shown in this figure. This willoccur before the wheels 34 and 42 move off the rail means 30 and 40 sothat when this move off occurs the stools 52 will serve to keep therolls in the separated condition. It will be noted that the outside endof each rail 30 has a slight inclination which allows the upper chock 14to be set easily onto the top of stools 52. The lower wheels 42 willmove onto the upper ends of the plates 140 and 142' as they pass fromrails 40.

Continued movement of the work rolls out of the mill will bring thedrive side chocks 14 and 16' into engagement with the drive side stools62. The stools 62 thus move into the cavities 100 and 102 to theposition illustrated by the dashed line showing of stools 62 in FIG. 4.Thus, when the drive side chocks l4 and 16 move off the rails 30 and 40within the mill, the stools 62 serve to maintain them in the separatedcondition.

When the new set of rolls is inserted into the mill an action occurswhich is essentially the reverse of that described above during theremoval of the work roll chocks. ln other words, the drive side stools62 will be picked up by the stool supporting rails 58 at the solid lineposition shown in FIG. 4. Thus, the stools 62 are held in this positionby reason of the latch means 59 and the limiting action of the inclinedportion 63. Continued movement of the work roll chocks into the millwill subsequently cause the operator side stools 52 to be picked up bythe stool support rails 58 at the solid line position shown in FIG. 4.Again this occurs by reason of the latch means 59 and the limitng actionof the inclined portion 61.

By reason of the above described arrangement it will only be necessaryto have two sets of stool means 50 and 60 for each mill/One set of stoolmeans is to be retained in the mill during rolling while the other setof stool means will be'used in the preparation of the new work rollswhich are to be inserted into the mill to replace the worn work rolls.

lt will be apparent that various changes may be made in the constructionand, arrangement of parts without departing from the scope of theinvention.

We claim:

1. [n a rolling mill having upper and lower work rolls defining a passline for the strip to be rolled therebetween, an operator side millhousing defining a window, upper and lower work roll chocks forrotatably supporting the upper and lower work rolls and adapted to beremovably mounted in said operator side housing, a mill housing on thedrive side of the mill defining a window, an upper and lower work rollchock for rotatably supporting the upper and lower work rolls on thedrive side of the mill and adapted to be removably mounted in said driveside housing window, means for supporting said work roll chocks and saidwork rolls supported thereby in a separated condition during movementthereof inside of the mill housing, means for supporting said work rollchocks and the work roll supported thereby in separated condition duringmovement outside of the mill housing, said last-named means comprisingfirst stool means positioned within said operator side housing andadapted to be positiond between said operator side work roll chocks andsecond stool means positioned within said operator side housing andadapted to be positioned between said drive side work roll chocks, andmeans for supporting said first and second stool means in said operatorside housing window at a location between said upper and lower work rollchocks.

2. ln a rolling mill according to claim 1 wherein said operator sidework roll chocks have opposed cavities adapted to contain said first andsecond stool means during a rolling operation.

3. A rolling mill according to claim 2 wherein said operator side workroll chocks contain cavities adapted to receive and pick upsaid firststool means as the work rolls are moved toward the outside of the millduring a work roll changing operation.

4. A rolling mill according to claim 3 wherein said drive side work rollchocks comprise opposed cavity portions adapted to receive and pick upsaid second stool means as the work rolls are moved toward the outsideof the mill during a work roll changing operation.

5. A rolling mill according to claim 1 wherein said supporting means forsaid first and second stool means comprises horizontally extending railmeans.

6. A rolling mill according to claim, 5 including a pair of latch meansholding said first and second stool means at a desired position on saidrail means and limiting movement thereof in the direction toward theinside of the mill whereby as work rolls are moved into the mill duringa work roll changing operation said first and second stool means will bedeposited onto said rail means at said limiting positions.

7. A rolling mill according to claim 1 including a side shift caradjacent said operator side housing and having means providing two pairsof rails adapted to receive and support said work roll chocks outside ofthe mill.

8. A rolling mill according to claim 7 wherein said means for providingsaid rails on said side shift car comprises floor plates adapted to bemoved from a horizontal position providing a floor area and an uprightposition whereat the upper ends thereof provide said rails forsupporting said work roll chocks.

9. A rolling mill according to claim 1 wherein said means for supportingsaid work roll chocks during movement inside the mill includes railsextending be tween said drive side mill housing and said operator sidemill housing.

10. A rolling mill according to claim 9 wherein said supporting meansfor said first and second stool means comprises horizontally extendingrail means.

11. A rolling mill according to claim 10 including a pair of latch meansholding said first and second stool means at a desired position on saidrail means and limiting movement thereof in the direction toward theinside of the mill whereby as work rolls are moved into the mill duringa work roll changing operation said first and second stool means will bedeposited onto said rail means at said limiting positions.

12. A side shift car for use in automatic changing of the work rolls ofa mill stand of a rolling mill comprising a frame located adjacent themill stand below the floor line of the mill and adapted to be shiftedbetween a pair of roll changing positions, power operated means foractuating said frame between said pair of roll changing positions, andmeans mounted on said frame providing two pair of rails adapted tosupport two sets of work rolls at a location adjacent the rolling millstand,'said rail providing means comprising a plurality of floor platesmounted for movement between a horizontal position in which said floorplates provide a floor area adjacent the rolling mill and an uprightposition in which the upper ends of said floor plates providehorizontally extending rails adapted to support said work roll, thefloor plates providing each pair of rails being positioned inedge-to-edge relationship in said horizontal position thereof to providea closed floor area, one of said pair of rails in said upright positionthereof being aligned with said mill stand when said frame is in one ofsaid pair of roll changing positions, the other of said pair of rails insaid upright position thereof being aligned with said mill stand whensaid frame is in the other of said pair of roll changing positions.

13. A side shift car according to claim 12 in which said floor platesare pivotally mounted on horizontally extending pivots and includinglink means associated with each pair of rail forming floor plates forinterconnecting the same for conjoint movement.

14. A side shift car according to claim 13 including power operatedmeans associated with each pair of linked floor plates for actuating thesame between said horizontal and upright positions thereof.

15. In a rolling mill having upper and lower work rolls defining a passline for the strip to be rolled therebetween, an operator side millhousing defining a window, upper and lower work roll chocks forrotatably supporting the upper and lower work rolls and adapted to beremovably mounted in said operator side housing, a

mil] housing on the drive side of the mill defining a window, and upperand lower work roll chock for rotatably supporting the upper and lowerwork rolls on the drive side of the mill and adapted to be removablymounted in said drive side housing window, means for supporting saidwork roll chocks and said work rolls supported thereby in a separatedcondition during movement thereof inside of the mill housing, and meansfor supporting said work roll chocks and the work roll supported therebyin separated condition during movement outside of the mill housing, saidlast-named means comprising first stool means positioned within saidoperator side housing and second stool means positioned within saidoperator side housing, said operator side work roll chocks havingopposed recessed cavities adapted to receive and contain said first andsecond stool means during a rolling operation with said work rolls in aclosed condition.

16. A rolling mill according to claim 15 wherein said operator side workroll chocks contain cavities adapted to receive and pick up said firststool means as the work rolls are moved toward the outside of the millduring a work roll changing operation.

17. A rolling mill according to claim 16 wherein said drive side workroll chocks comprise opposed cavity portions adapted to receive and pickup said second stool means as the work rolls are moved toward theoutside of the mill during a work roll changing opera-

1. In a rolling mill having upper and lower work rolls defining a passline for the strip to be rolled therebetween, an operator side millhousing defining a window, upper and lower work roll chocks forrotatably supporting the upper and lower work rolls and adapted to beremovably mounted in said operator side housing, a mill housing on thedrive side of the mill defining a window, an upper and lower work rollchock for rotatably supporting the upper and lower work rolls on thedrive side of the mill and adapted to be removably mounted in said driveside housing window, means for supporting said work roll chocks and saidwork rolls supported thereby in a separated condition during movementthereof inside of the mill housing, means for supporting said work rollchocks and the work roll supported thereby in separated conditioN duringmovement outside of the mill housing, said last-named means comprisingfirst stool means positioned within said operator side housing andadapted to be positiond between said operator side work roll chocks andsecond stool means positioned within said operator side housing andadapted to be positioned between said drive side work roll chocks, andmeans for supporting said first and second stool means in said operatorside housing window at a location between said upper and lower work rollchocks.
 2. In a rolling mill according to claim 1 wherein said operatorside work roll chocks have opposed cavities adapted to contain saidfirst and second stool means during a rolling operation.
 3. A rollingmill according to claim 2 wherein said operator side work roll chockscontain cavities adapted to receive and pick up said first stool meansas the work rolls are moved toward the outside of the mill during a workroll changing operation.
 4. A rolling mill according to claim 3 whereinsaid drive side work roll chocks comprise opposed cavity portionsadapted to receive and pick up said second stool means as the work rollsare moved toward the outside of the mill during a work roll changingoperation.
 5. A rolling mill according to claim 1 wherein saidsupporting means for said first and second stool means compriseshorizontally extending rail means.
 6. A rolling mill according to claim5 including a pair of latch means holding said first and second stoolmeans at a desired position on said rail means and limiting movementthereof in the direction toward the inside of the mill whereby as workrolls are moved into the mill during a work roll changing operation saidfirst and second stool means will be deposited onto said rail means atsaid limiting positions.
 7. A rolling mill according to claim 1including a side shift car adjacent said operator side housing andhaving means providing two pairs of rails adapted to receive and supportsaid work roll chocks outside of the mill.
 8. A rolling mill accordingto claim 7 wherein said means for providing said rails on said sideshift car comprises floor plates adapted to be moved from a horizontalposition providing a floor area and an upright position whereat theupper ends thereof provide said rails for supporting said work rollchocks.
 9. A rolling mill according to claim 1 wherein said means forsupporting said work roll chocks during movement inside the millincludes rails extending between said drive side mill housing and saidoperator side mill housing.
 10. A rolling mill according to claim 9wherein said supporting means for said first and second stool meanscomprises horizontally extending rail means.
 11. A rolling millaccording to claim 10 including a pair of latch means holding said firstand second stool means at a desired position on said rail means andlimiting movement thereof in the direction toward the inside of the millwhereby as work rolls are moved into the mill during a work rollchanging operation said first and second stool means will be depositedonto said rail means at said limiting positions.
 12. A side shift carfor use in automatic changing of the work rolls of a mill stand of arolling mill comprising a frame located adjacent the mill stand belowthe floor line of the mill and adapted to be shifted between a pair ofroll changing positions, power operated means for actuating said framebetween said pair of roll changing positions, and means mounted on saidframe providing two pair of rails adapted to support two sets of workrolls at a location adjacent the rolling mill stand, said rail providingmeans comprising a plurality of floor plates mounted for movementbetween a horizontal position in which said floor plates provide a floorarea adjacent the rolling mill and an upright position in which theupper ends of said floor plates provide horizontally extending railsadapted to support said work roll, the floor plates providing each pairof rails being positioned in edge-To-edge relationship in saidhorizontal position thereof to provide a closed floor area, one of saidpair of rails in said upright position thereof being aligned with saidmill stand when said frame is in one of said pair of roll changingpositions, the other of said pair of rails in said upright positionthereof being aligned with said mill stand when said frame is in theother of said pair of roll changing positions.
 13. A side shift caraccording to claim 12 in which said floor plates are pivotally mountedon horizontally extending pivots and including link means associatedwith each pair of rail forming floor plates for interconnecting the samefor conjoint movement.
 14. A side shift car according to claim 13including power operated means associated with each pair of linked floorplates for actuating the same between said horizontal and uprightpositions thereof.
 15. In a rolling mill having upper and lower workrolls defining a pass line for the strip to be rolled therebetween, anoperator side mill housing defining a window, upper and lower work rollchocks for rotatably supporting the upper and lower work rolls andadapted to be removably mounted in said operator side housing, a millhousing on the drive side of the mill defining a window, and upper andlower work roll chock for rotatably supporting the upper and lower workrolls on the drive side of the mill and adapted to be removably mountedin said drive side housing window, means for supporting said work rollchocks and said work rolls supported thereby in a separated conditionduring movement thereof inside of the mill housing, and means forsupporting said work roll chocks and the work roll supported thereby inseparated condition during movement outside of the mill housing, saidlastnamed means comprising first stool means positioned within saidoperator side housing and second stool means positioned within saidoperator side housing, said operator side work roll chocks havingopposed recessed cavities adapted to receive and contain said first andsecond stool means during a rolling operation with said work rolls in aclosed condition.
 16. A rolling mill according to claim 15 wherein saidoperator side work roll chocks contain cavities adapted to receive andpick up said first stool means as the work rolls are moved toward theoutside of the mill during a work roll changing operation.
 17. A rollingmill according to claim 16 wherein said drive side work roll chockscomprise opposed cavity portions adapted to receive and pick up saidsecond stool means as the work rolls are moved toward the outside of themill during a work roll changing operation.